A conventional bicycle steering bearing assembly is connected to two ends of the head tube of a bicycle frame and the steerer tube extends through the head tube and is cooperated with the two bearing assemblies so that the steering tube can be freely rotated relative to the head tube. There are several small parts involved in the conventional steering bearing assembly and the conventional seal device is connected to the steering bearing assembly to prevent dust and water from entering the steering bearing assembly. However, the conventional seal device includes several pieces which include at least two grooves defined in an outer periphery of the cover so as to receive two seal rings therein. Although the seal rings successfully seal the dust and water, it is noted that the grooves are so tiny so that special tool and skill are needed to manufacture the grooves in a small part. Besides, it takes a lot of time to assemble the conventional seal device to the steering bearing assembly.
The present invention intends to provide a seal device for a bicycle steering bearing assembly and the seal device is effective, includes less number of parts, and is easily assembled to the bearing assembly.